1. Technical Field
The present invention relates to an actuator device.
2. Description of the Related Art
LI Na et. al. disclose coiled and non-coiled twisted nanofiber yarn and polymer fiber torsional and tensile actuators in WO2014/022667. Maki Hiraoka et. al. disclose a colied polymer fiber formed of linear low-density polyethylene in the poster having a title of “Large strains and their polymer chain morphologies on coiled polymer fiber actuators”, which was released at the symposium of the 24th Polymer Material Forum, which was held on Nov. 26, 2015, in Tokyo, JAPAN. According to Maki Hiraoka et. al., the colied polymer fiber is capable of being contracted by application of heat and being restored by release of heat. Kukolj discloses an axially contractable actuator in U.S. Pat. No. 4,733,603.